Tire Pressure (again}

[chessie4905]

Face it. This country is run by lawyers. You notice politicians don't  attack the legal profession, there is no regulation on them."You don't  pay unless we win"), they typically get 30 to 50 percent of the proceeds of a winning lawsuit. They are advertising everywhere on tv anymore. Class action lawsuits on drugs, cars, toys, food, medical mail practice, hospitals, etc,etc.
Their time will eventually come. This is not to say many suits have been beneficial over the years. Notice how many Senators and Representatives are from or go to the legal profession when they retire.

[Jim Blackwood]

Well, all the politicians are lawyers anyway.

[DoubleEagle]

To be fair, some of the politicians are doctors, farmers, and at least one bar maid. The vast majority are lawyers, though, and it always seemed to me that it was a conflict of interest for lawyers to pass laws that they would benefit from when in law practice. This whole tire inflation level thing sounds like an attempt for tire companies to avoid litigation when one of their tires cause an accident. That is why tire pressure sensors are now provided on many cars. It still makes sense to know the weight on each tire position, and adjust the pressure to provide even tire wear with heat levels that will not increase the risk of tire failure.

[TomC]

Quite simply-they are covering their butts. If you run at maximum tire pressure on the side of the tire, you'll have a ride like a fork lift. I still maintain to weigh your bus at the heaviest (everything full) and then consult your manufacturers tire inflation table. Then run about 5psi higher. Good Luck, TomC

[chessie4905]

Actually, few ever spend the time or money to get their coaches weighed at each corner. Not that it is that expensive either.

[TomC]

Getting it weighed at each corner isn't that accurate since most air ride buses have a single leveling valve in the front that makes for exactly the same weight on the right and left. But on the rear-you could have it heavier on one side or the other. The only real way to find out is to weigh. Good Luck, TomC

[dtcerrato]

Good point Tom on the tripod leveling system. It's sometimes hard to figure but yes the front is equal weight on both sides of the axle.

[luvrbus]

Not all buses have a front axle,the only way you can balance one with Independent front suspension is weigh both sides,you would be in a world of hurt on a Eagle thinking it would be the same on both sides     

[chessie4905]

Drain the airbags on the front axle to get individual corner weights. Tom, doesn't  the air in bags just level the coach? Wouldn't the wheel weight stay the same? I'll  have to try that when I get mine weighed.

[DoubleEagle]

I am deprived of all airbags, but it seems to me that if the weight on one side of the front suspension is greatly different, and yet the bus is level, there would have to be greater pressure in the airbag on that side to hold it up level. If the pressure could be measured, it should indicate the difference, just as in the case of a hydraulic jack with a oil pressure gauge.

[dtcerrato]

The air in the front suspension (at least on our 4104) is equal on both sides... It has to be. It's one system with no point of separation between the sides. The moment all the air front is exhausted to see what the difference in side by side weight is - the rear weight difference from side to side is being transferred to the front because the cushion of air to enable the whole front to act as one system is gone to independent solid mechanical points on each side. 

[DoubleEagle]

If that is the case then, it would seem that if the bus were particularly heavy on one side, it would not be level, or is there something else at play?

[dtcerrato]

The rear air suspension is independent on each side with two separate leveling valves. The difference in side to side weight is sensed by only rear leveling valves to compensate so bus is level. The word level is also misleading because it doesn't mean bus body level with ground - it means bus body level with rear axle. If your rear axle is on side to side unlevel ground so will be the body. The front leveling valve (1 common to both sides) will compensate for front to back level between the bus body & front axle - not the ground. We really never had a clear understanding of the tripod system untill we installed manually operated solenoids to level the bus "body" with the ground during parking or camping and that system is only good for a max of almost 4" inches difference across all corners. Think of a 3 legged stool on uneven floor - it won't rock as a 4 legged stool would.

[richard5933]

...The word level is also misleading because it doesn't mean bus body level with ground - it means bus body level with rear axle. If your rear axle is on side to side unlevel ground so will be the body. The front leveling valve (1 common to both sides) will compensate for front to back level between the bus body & front axle - not the ground...

What he said.

Substitute the word 'parallel' for level and it makes even more sense.

When we got our first bus it drove me crazy that it looked crooked every time we parked on our driveway, but straightened up once we got on the road. I was expecting the suspension to keep it level, when all the while it was doing its best to keep the body parallel to the rear axle.

[luvrbus]

The only way the weight could be the same on both sides is if the axle had a pivot point in the center all your front end loaders and rubber tired construction equipment uses the center pivot to achieve that.
I have seen it many times over the years at Marathon,Country Coach and Vogue a Prevost shell setting on 6 scales as they do the conversion process and they pay close attention at the side loading on the front axle.John and Walter have it right